What is a single-positive and double-positive nucleic acid test for novel coronavirus pneumonia, and what is the difference between them?
According to the Technical Guide for Laboratory Testing of Novel Coronavirus Pneumonia (4th Edition), the nucleic acid test for neo-coronavirus is a real-time fluorescent RT-PCR method that targets the open reading frame 1ab (ORF1ab) and the nucleocapsid protein (N) of the novel coronavirus genome. nucleocapsid protein (N).
Usually, positive patients are positive for both ORF1ab and N genes, but they may also be positive for one of the ORF1ab or N genes, which is called single positive. For cases with single positive nucleic acid test for appealing new coronavirus, it is still necessary to take another sample for real-time fluorescence RT-PCR to determine if it is case positive.
What is an asymptomatic infected person, by what means is it found and are the cases infectious?
Zhang Guojun told reporters that according to the Novel Coronavirus Pneumonia Prevention and Control Program (6th Edition), an asymptomatic infected person is a person who is infected with a novel coronavirus but has no clinical symptoms (such as fever, cough, sore throat, etc.), but whose respiratory tract and other specimens are positive for novel coronavirus pathogenesis or serum-specific IgM antibody testing.
The "Pneumonia Case Surveillance Program for Novel Coronavirus (Third Edition)" released on January 28 distinguishes between "asymptomatic infections" and suspected, confirmed, and mild cases, and excludes from the daily release of confirmed cases if the nucleic acid test is positive for novel coronavirus but there are no symptoms. However, strict management measures should still be implemented for asymptomatic infections. Asymptomatic infections should be isolated for 14 days, and when the isolation period expires, those with two consecutive specimens negative for nucleic acid testing can, in principle, be released from isolation. Those who develop symptoms during isolation will be immediately admitted to hospital.
Asymptomatic infected persons are found mainly through close contact screening, aggregated outbreak investigation and source tracing investigation. A small number of asymptomatic infections may develop into confirmed cases, but the vast majority will recover spontaneously.
Asymptomatic infections can also be a source of infection and carry some risk of transmission. The current management of asymptomatic infections is isolation upon detection, continued nucleic acid testing and further observation for symptoms during isolation, and also intervention with some antiviral drugs. In principle, two consecutive negative nucleic acid tests are required before isolation can be lifted.
What is the difference between a single positive and a double positive nucleic acid test for Newcastle pneumonia?
According to the Technical Guide for Laboratory Testing of Novel Coronavirus Pneumonia (4th Edition), the nucleic acid test for neo-coronavirus is a real-time fluorescence RT-PCR method that targets the open reading frame 1ab (ORF1ab) and nucleocapsid protein (Nucleocapsid protein) of the novel coronavirus genome. nucleocapsid protein (N).
Usually, positive patients are positive for both ORF1ab and N genes, but they may also be positive for one of the ORF1ab or N genes, which is called single positive. In cases with single positive nucleic acid test for the new coronavirus on appeal, it is still necessary to take another sample for real-time fluorescence RT-PCR to determine whether the case is positive or not.
